Compression point

The compression point is a metric describing an aspect of electronic amplifiers. For example, the 1-dB compression point (sometimes notated as P1dB^[1][2]) is the output power of the amplifier (for the signal of interest) at which it differs from an ideal linear amplifier by more than 1 dB. So a larger 1-dB compression point means that the amplifier can produce larger outputs (for the same amount of distortion).^[3] It will often be quoted by manufacturers of amplifiers^[4]..^[5]

1 dB compression point (P1dB) on a graph of the transfer function (in German). An ideal amplifier will produce a straight line (German: ideale Kennlinie). A real-world amplifier has an output power limit and will therefore exhibit gain compression (German: reale Kennlinie)

The compression point is sometimes used (interchangeably with the third-order intercept point) to define the upper limit of the dynamic range of an amplifier. A rule of thumb that holds for many linear radio-frequency amplifiers is that the 1 dB compression point point falls approximately 10 dB below the third-order intercept point.^{[citation needed]}